Temporal Sequence of Cognitive Function and ADLs and Mediation Effect of Apathy in Parkinson's Disease: Cross-Lagged
Xiaofang Cui1,2, Xiao Lu1, Sidan Du1
1Department of Health Statistics, School of Public Health, Shanxi Medical University, Taiyuan, China.
Objectives:
To explore the temporal sequence between cognitive function and activities of daily living (ADLs) in patients with Parkinson's disease (PD) and investigate whether apathy mediates these effects.
Methods:
We recruited 486 patients from the Parkinson's Progression Marker Initiative. We constructed a cross-lagged panel model to explore the temporal sequence between cognitive function and ADLs and analyzed the longitudinal mediating effect of apathy on the relationship between cognitive function and ADLs.
Results:
The slopes of ADLs and cognitive function were significant (p < .001), and lower levels of cognitive function indicated lower ADLs, suggesting that a decreased cognitive performance preceded ADLs decline. Cognitive function influenced apathy (negatively) (p < .001) and ADLs (p < .001). A significant indirect effect of cognitive function on ADLs through apathy was revealed by bias-corrected bootstrapping (β = 0.181, p < .001).
Conclusions:
The rate of change in cognitive function was significantly correlated with that of ADLs, and a decreased cognitive performance preceded ADLs decline. Cognition was indirectly related to ADLs through apathy.
Clinical Implications:
The rate of change in cognitive function in patients with PD was correlated with that of ADLs, and a decreased cognitive performance preceded ADLs decline. Reducing apathy represents a promising approach to reducing the impact of cognitive decline on ADLs.
